Patent US 6,327,741

A controlled self operating vacuum cleaning system which comprises a stationary housing for the storage of a mobile vacuum cleaner apparatus and where the housing is provided with an automatically openable and closable closure allowing exit and entry of the mobile vacuum cleaner unit. The mobile unit is driven by an internal drive motor which is powered by one or more batteries carried by the mobile vacuum cleaner unit. At preestablished times and preestablished time intervals, the closure of the housing will automatically open providing for ingress and egress and the mobile vacuum cleaner unit will exit and randomly clean the carpet of a certain specified area for a predetermined time period. The mobile vacuum cleaner unit is provided with obstacle detectors for causing the mobile unit to move beyond an obstacle, if it contacts an obstacle, as well as detectors for detecting the edge of a staircase and the edge of a carpet to cause the mobile unit to remain on the carpeted area. Upon return to the housing after the predetermined time interval, the mobile vacuum cleaner unit is automatically connected to a recharging electrical circuit for recharging the batteries of the mobile vacuum cleaner unit and simultaneously an additional vacuum dirt collection system causes evacuation of the dirt collected by the mobile cleaner unit.